The study uses functional magnetic resonance imaging (fMRI) to compare the effects of paroxetine, an SSRI, versus bupropion, a non-SSRI, on brain activity in depressed patients with a past suicide attempt and/or current suicidal thoughts. Participants are randomly assigned to either paroxetine or bupropion treatment for 8 weeks, with fMRI scans involving a reward processing task at baseline and Week 8. Weekly study visits include interviews with a psychologist, self-report scales, and medication monitoring. All participants will then be offered 4 additional months of open clinical treatment. If original medication assignments prove to be ineffective, participants will have the option to switch to another medication. After completing the study, participants will be referred for ongoing treatment.